Water constitutes the largest portion, by weight, of a food animal. From about the time such an animal is slaughtered, its carcass begins to lose water, dry out or shrink. Shrinkage or weight loss, which begins on slaughtering, continues not only through the refrigeration and butchering steps in meat processing, but also during cooking. As a result of shrinkage, the meat generally becomes somewhat tougher and can be harder to butcher. As a further result of this shrinkage, the meat provider obtains a lesser amount of product to sell, and that product is of diminished quality. Because of shrinkage, the meat purchaser receives an even smaller amount of product to cook, and cooking shrinkage results in a still smaller amount of cooked material served for ultimate consumption.
Several processes are known in the art which are said to minimize or reverse carcass shrinkage. Among these are processes in which meat is sprayed or fogged with an aqueous solution, or in which meat is dipped into a water bath. In addition, it is well known to use aqueous curing compositions or pickles which assist in reducing meat shrinkage while preserving and flavoring the meat.
In some anti-shrink techniques in which water is added back to the carcass, or its meat, to return the water content to a natural level, it is found that such water is usually not held firmly therein and is lost again on processing. For example, it is known and usual in pork sausage manufacture to mix 1,000 pounds of pork chunks with up to 31 pounds of a brine solution containing 30 pounds of water and one pound of salt (sodium chloride). About one minute or more may be required for the pork chunks to become moisturized by sorbing the brine. Then, during further processing, when the moisturized pork chunks are ground, shrinkage again is manifest in that some water is lost from the ground, moisturized chunks, thereby lowering the yield of ground meat produced. When sausages containing 60 weight-% lean--40 weight-% fat ground pork are prepared by this known and usual method, and are cooked with continual rolling at a temperature of about 340.degree.-350.degree. F. for 10 minutes under standard conditions, it is observed that they shrink to about 38-43% of their precooked weight, or maintain about 62-57% of that weight. In addition, air pockets are often noted between the sausage casing and the meat therewithin, and the sausages curl.
In the curing arts, meats, particularly certain cuts of beef and pork, are cured by contacting the meat with aqueous curing solutions or dispersions, and maintaining that contact for a time sufficient to cure the meat. Methods for contacting the meat with aqueous curing solutions called aqueous pickle solutions or pickles include bathing the meat by total or partial submersion in the pickle, injecting the pickle into the meat through available indigenous vasculature, or by injecting the pickle into the meat through hollow needles that penetrate through the meat's surface. Each of these methods is frequently used alone, but more frequently, one or more of the aforementioned methods is used in conjunction with the others. In most common practice, pickle is injected into the meat at random locations, and the meat bathed with pickle by submersion therein. Bathing by submersion alone, or injection via available veins or arteries, are usually too inefficient for today's productivity requirements.
Aqueous pickle solutions are primarily composed of water to which salts, flavorants and preservatives are added. Thus, aqueous pickle solutions may contain edible chlorides such as sodium, potassium or calcium chloride, edible phosphates such as sodium pyrophosphate, tripolyphosate, hexametaphosphate, disodium phosphate and the like, sugars such as sucrose, spices, edible gums, smoke distillates, and the like, as well as preservatives such as sodium nitrate and sodium nitrite.
Examination of pickling compositions known in the art reveals that polyvalent curing and buffering agents such as phosphate and carbonate salts frequently constitute an important portion of the pickle solution. The ranking by weight of importance of these salts in typical aqueous pickle solutions is normally third or fourth, after water, an edible chloride salt such as sodium chloride and a sugar such as sucrose or corn syrup. This is shown in U.S. Pat. Nos. 2,812,262; 3,028,246; 3,076,713; 3,215,540; 3,240,612 and 3,255,023.
One major problem with curing and preserving meat is shrinkage, since on going from its fresh state to the cured, cooked condition, the meat loses moisture, protein and fats. Shrinkage of about 20-25% of the original weight of the meat including the injected pickle solution is a common result for cured products after they are smoked and cooked. Thus, relative to the fresh product, the meat supplier again has less meat to sell, and the purchaser again has less meat to buy.
One of the principal purposes for the inclusion of phosphates, carbonates and similar polyvalent curing and buffering agents in aqueous pickle solutions is to help prevent shrinkage in the cured, cooked products. This expedient is taught in U.S. Pat. Nos. 3,028,246 and 3,215,540. For example, these patents teach that yields of cooked products cured with phosphate salt-containing pickle solutions may range from near 90% to greater than 100% by weight of the freshly deboned meat.
It is also known in the art that meat may be treated by placing the meat into an aqueous brine solution and passing an electric current therethrough. These treatments are shown in U.S. Pat. No. 267,684, No. 657,207, No. 705,367, No. 760,173, and No. 930,772. In each of these treatments, the meat is within the aqueous brine solution while the current is passed. These treatments are said to improve the rate of meat curing.
It would be beneficial to the meat product suppliers and the consuming public if shrinkage were reduced in meat products as sold and as used after cooking. It would also be beneficial if cured meat products could be produced in greater yield using pickle solutions similar to those already in use, or even at currently achievable yields, but by using pickle solutions from which some of the usual ingredients, such as phosphate salts, are omitted.